You could equally argue that the 'home advantage' actually added pressure to the French, and doesn't really represent much of a home advantage for, particularly, England (Ireland and Wales perhaps).
I think it is generally accepted that NH sides will find it that bit harder playing in the SH and vice versa, not least due to the challenges of time zones and effectively having to adjust to a completely different season (you do understand that our physiology doesn't like that!). It is pretty hard to argue that NZ, SA and Argentina were somehow advantaged by playing in France compared to France, Wales and Ireland.
It might be a continuation of that pattern, but the fact that there is so much discussion about how it's surprising that all three matches went the way of the SH sides suggests that perhaps it's not. We could be at the stage where the SH sides are not significantly better, as they have been in the past, but rather it was just the 'statistical aberration' of close sides separated by the bounce of the ball. In order to demonstrate that the NH sides now need to build on this and stay competitive - the SH status isn't built on one tournament, but rather on their consistent ability to operate at or near the top. The NH sides have periodically had one side or another have a peak, but rarely have they had two or three sides in the top five, rarely have they had two sides in realistic consideration for a major tournament.
But it never seems to drop the other way does it. I get it that sometimes there are slim margins, there are critical decisions and ball bounces that make the difference between winning and losing. But over time you'd expect these things to even out - sometimes the SH sides get the rub of the green sometimes the NH sides. But that isn't the case here - when push comes to shove in the world cup the SH sides come out on top - and when that happens as a continuing pattern you have to look beyond the rub of the green, the fine margins. And accept the clear conclusion - that the SH teams are just better - 8 (likely 9 in a couple of weeks) world cups to 1 tells its own story.
And it may be that the pressure of a tournament is playing a part, a legacy of that sense of the having been there and done it vs it being new territory,
I think that's part of it - the big three SH sides simply have a heritage of winning the world cup - they know how to do it. The NH sides (with the exception of England) don't. And that probably plays into the mentality side of things - the SH sides simply expect to come out on top and guess what, they do.
... but I don't accept the notion that the All Blacks or the South Africans play any less intensely outside of the World Cup than they do in any other competitive match.
But the SH sides don't play NH sides in properly competitive fixtures except at the world cup. The summer internationals down under and the autumn internations aren't really competitive at all - in many cases the matches are played by 'experimental' sides as teams use them as useful training exercises to blood new players, try new tactics, in a manner they'd never dream of doing in a world cup quarter final or semi final etc.
So the only time we really get to see who is top dog between SH and NH sides is once every 4 years at the world cup - and yet again we see the SH sides rising to the top.
I must admit I find this level of hand wringing complacency rather startling if you actually want to see NH sides genuinely competing against the SH sides at the world cup. While you continue to put it down to an unfortunate bounce of the ball or 'fine margins' the SH sides will continue to dominate. Only by accepting that they are, frankly, better will the NH rugby authorities start to look at what they need to do in terms of root and branch changes to the game in the NH to make them competitive.
But hey denial is a river in Egypt (not a tier 1 rugby playing nation).
